Most pre-printed documents, including many forms, handouts, school assignments, and publications, are typically printed with black characters on a white background. Colored marks that may be made on such documents might later be considered undesirable. A child, for example using a colored crayon or marker, may mark upon a document. Alternatively, an error might be made in filling out a tax return form or a loan application using a blue pen. Attempting to remove or obscure such markings using correction fluid, or by ‘striking out’ the error, generally produces a messy and unprofessional looking document, and may even render the document illegible. However, unless a clean copy of the original document is available, the marked-upon copy must be used, potentially causing frustration and/or embarrassment. It would be useful to provide a convenient mechanism to rehabilitate such documents, so that they could be used, or reused. It would also be useful to be able to remove such markings from coloring sheets, or other children's activity sheets, so that such documents could be reused, thereby reducing the expense of purchasing additional copies.